Process for sizing textile fibres

ABSTRACT

Process for sizing slivers or rovings of textile fibres in which the slivers or rovings are unwound from a supply thereof and are accelerated progressively and smoothly to a given speed by a pulling force which is always less than the cohesion force between the fibres constituting the slivers or rovings. The slivers or rovings are then flattened by passing between a first pair of pressure rollers, before dipping into a bath of size and then passing through a second pair of pressure rollers to be forwarded onto a drier for drying the size whereafter they are wound up on a bobbin. The size has the effect of gluing the fibres of slivers or rovings together and imparts sufficient cohesion for the slivers or rovings to be worked as such in a loom or knitting machine. The size may subsequently be removed after manufacture of a textile article from the slivers or rovings.

United States Patent 1191 Schutz et al.

[ Feb. 12, 1974 PROCESS FOR SIZING TEXTILE FIBRES [75] Inventors:Richard Adrien Schutz; Pierre Elisee Exbrayat, both of Mulhouse, France[73] Assignee: Centre Technique Industriel: lnstitut Textile De France,Boulogne Sur Seine, France {22] Filed: Dec. 1, 1971 [21] Appl. No.:203,720

3,093,504 6/1963 Bode 28/72.6 X

3,154,908 11/1964 Cilker et a1. 57/2.5 X

Primary Examiner-Louis K. Rimrodt 5 7] ABSTRACT Process for sizingslivers or rovings of textile fibres in which the slivers or rovings areunwound from a supply thereof and are accelerated progressively andsmoothly to a given speed by a pulling force which is always less thanthe cohesion force between the fibres constituting the slivers orrovings. The slivers or rovings are then flattened by passing between afirst pair of pressure rollers, before dipping into a bath of size andthen passing through a second pair of pressure rollers to be forwardedonto a drier for drying the size whereafter they are wound up on abobbin. The size has the effect of gluing the fibres of slivers orrovings together and imparts sufficient cohesion for the slivers orrovings to be worked as such in a loom or knitting machine. The size maysubsequently be removed after manufacture of a textile article from theslivers or rovmgs.

8 Claims, 3 Drawing Figures PATENTEDFEB 12 1974 SHEET 1 OF 2 InventorKmhard Hdnsn Schu tz Dvsvre Ehs ea Exbraqar PROCESS FOR SIZING TEXTILEFIBRES The present invention relates to a process and an apparatus forsizing textile fibres, more particularly to a process and apparatus forsizing textile fibres in the form of slivers or rovings, and to textilearticles formed therefrom.

Conventionally, articles such as fabrics, knitwear etc., are formed withthe aid of textile fibres in the form of a yarn. This yarn should have asuppleness, an elasticity and resistance sufficient to enable it to besubjected, without damage, to the diverse constraints occasioned by itsmanipulation during the course of the operations of weaving or ofknitting.

For this purpose, the conventional yarn, obtained by spinning a textileraw material, is more or less twisted, in order to improve the cohesionbetween the fibres constituting the yarn, then, in this state issubjected to sizing, when it is intended to form the warp of a fabric.

This spinning can, in general, be divided into two successive stages inwhich, in a number of cases present the same importance andsubstantially the same cost price. During the first stage, calledpreparation, the textile material in the form of bales is treated byheating and then by carding to give a web, the textile fibres beingdistributed in a homogeneous fashion and oriented preferentially in thesense of advance of the web, the latter being eventually subdivided toform slivers. These are subjected to doubling and drawing to giverovings. The slivers generally have hundreds of thousands of fibres tothe section, such that the roving comprises thousands of fibres to thesection; but it is possible to obtain a roving of desired fineness bysuitable drawing.

During the second stage of the spinning proper, the rovings are madefiner by successive drawing, until one obtains a yarn in which thenumber of fibres to the section can fall to less than 50. The fibresthen receive a number of turns of twist to form a yarn giving therequired resistance and elasticity. The yarns are then fed to a loom orknitting machine to produce the textile article.

This conventional technique of fabrication of textile articles is longand costly. Moreover, the twist of the fibres looses a large part of theability to cover the fibres constituting the yarn.

It has already been proposed to omit the operation of the twisting ofthe yarn, effected usually during the second stage of the treatment ofthe yarn and to replace this twisting by a sizing operation.

According to a known process of manufacture, of a yarn without twist,the slivers and rovings of the textile fibres are drawn until oneobtains a very thin band which is impregnated with size; then the sizedfibres of this band are re-grouped in such a manner as to form a yarn ofsubstantially circular section which is then dried.

A known sizing apparatus for the purpose of putting into operation thisprocess comprises in particular: a first drawing train for the sliversor rovings of textile fibres unwound from a bobbin; an endless conveyorbelt for feeding the textile fibres leaving the first drawing train inthe form of a very thin band to the point where they are sized; twoparallel coating rollers defining between them a space sufiicient toreceive the size and deposit it on the walls of the band of fibres; atleast one forming roller defining with one of the coating rollers aspace situated on the path of the band of fibres downstream of thecoating space, the said forming rollers being given an axialreciprocating motion; two guiding rollers and a second drawing traindisposed on the path of the sized textile fibres downstream from thepoint of contact with the forming roller with the said textile fibres.

Another known installation comprises, in particular, an endless conveyorbelt furnished with a layer of size and of which the upper face is putin contact with the textile fibres leaving the drawing train.

In these installations, the textile fibres are coated with size bycontact with a guide surface of the fibres, this surface being coveredwith size.

This method of sizing has the disadvantage of transferring to the fibresan excessive quantity of size distributed in a hetrogeneous fashion.Moreover, the forming rollers of these apparatuses exercise on the thinband of fibres an alternating force which can create partial or totalrupture of the band of fibres and also produce irregularities in thethickness of the yarn obtained or in the distribution of the long andshort fibres in the yarn.

Furthermore, the known procedure takes away from the rovings theirinitial character and of necessity transforms them, by thinning, intoyarns in which the fibres are glued to one another along their length.

According to one aspect of the invention, there is provided a processfor sizing slivers or rovings of textile fibres, such process comprisingthe steps of unwinding the slivers or rovings from a supply thereof,applying a pulling force to the slivers or rovings progressively andsmoothly to accelerate the slivers or rovings to a given speed, saidpulling force always being slivers than the cohesion force between thefibres constituting the silvers or rovings; thereafter flattening theslivers or rovings; dipping the slivers or rovings into a bath of size;drying the sized slivers or rovings and winding up the sized slivers orrovings on a bobbin.

With such a process it is possible to form slivers or rovings which leadthemselves to the manufacture of textile articles of all sorts, such asnet or mesh articles, knitted articles, laps, carpets or tuftedarticles, or interlaced articles such as fabrics, without the necessityto transform the rovings into yarns.

Thus, the slivers or rovings are constituted by fibres glued partiallyto one another to acquire the necessary cohesion to be worked withoutsubstantial deformation. Moreover, such slivers or rovings lendthemselves without difficulty to the operations of weaving or knitting.The qualities of the textile article formed from the slivers or rovingstemporarily consolidated are fully evident after elimination of the sizeonce the article is manufactured.

These articles present then an exceptionally soft touch, a greatsuppleness, apparent increased volume and can be thermally insulatingand have a brilliance considerably superior to textile articles formedfrom a conventional yarn.

Because the sized slivers or rovings can be utilized directly on loomsor knitting machines, one saves, for a textile article formed fromrovings according to the invention, at least the cost price of thetransformation of the rovings into a twisted yarn or cable.

The invention also provides apparatus for forming sized slivers orrovings, such apparatus comprising a frame having a feed bobbin forslivers or rovings mounted for free rotation substantially withoutfriction therein; a vat of size, a first pair of pressure rollersmounted between said feed bobbin and said vat, a second pair of pressurerollers mounted downstream of said vat of size, a drier mounteddownstream of said second pair of rollers, a windup bobbin positioned toreceive slivers or rovings from said dryer and drive means to drive atleast one of the rollers of each of said pairs of pressure rollers at acontrolled speed. Thus, the slivers or rovings can be acceleratedprogressively and smoothly and the pulling force does not exceed thenatural cohesion force of the fibres and can be dipped into the bath ofsize without the fibres being pressed one against the other and withoutthe initial regularity of the rovings being destroyed.

Finally, the invention provides a textile article formed from slivers orrovings, which may be produced by the process or using the apparatus ofthe invention, and the slivers or rovings having fibres which are notheckled and have very little or no twist.

In order that the invention will more fully be understood, the followingdescription is given, merely by way of example, reference being made tothe accompanying drawings, in which:

FIG. 1 shows schematically one embodiment of apparatus according to theinvention;

FIG. 2 represents schematically the drive device for the pressurerollers and for the rollers of the drier; and

FIG. 3 is a perspective view of the rollers of the drier of theapparatus.

In FIG. 1, the feed bobbin 1 on which are wound slivers or rovings 2, ismounted so as to be freely rotatable without friction on the lateralpointed and coaxial ends 3. These ends 3 are located in ball bearings 4,mounted on an intermediate support 5 disposed on a frame 6, which itselfis capable of turning around an axis XX perpendicular to the axis of thebobbin 1 by means of a transmission formed by a pulley 7 associated witha drive belt 8.

The slivers or rovings 2 unwind from the bobbin 1 and pass successivelybetween a first pair of pressure rollers 9 and 10 disposed upstream of asize bath 11, then into the latter between a second pair of pressurerollers 12 and 13 disposed downstream of the said vat 11 and then into ahot drier 14.

The lower pressure rollers 10, 13 have smooth steel surfaces, whereasthe upper pressure rollers 9 and 12 can be covered with a substancehaving a high coefficient of friction for example rubber to ensure apositive drive to the fibres of the roving 2 between the pairs ofrollers 9, l0 and 12, 13.

The size vat 11 contains a bath of size 11a and is provided with a diproller 15 adjustable in height to guide and totally immerse the sliversor rovings 2 in the bath 1 la.

The temperature of the bath of size 11a is maintained constant by meansof a water bath 16 heated by a resistance 17 fed through a thermostat 18equipped with a contro thermometer 19.

The pressure rollers 9 and 12 are each provided with a pressureregulator comprising a lever 20 and 21, pivoted at one end 22 and 23,and carrying respectively a bearing for the shafts 24 and 25 of therollers 9 and 12, and at the other end weights 26 and 27 adjustable inposition.

After passage between the pressure rollers 12 and 13, the sized sliversor rovints 2' enter into the hot air drier 14 through an entry opening28 arranged laterally in the said drier 14 near its upper end.

Within the cabinet of the drier 14 are two series 29 and 30 of returnpulleys 29', 29" and 30', 30", the pulleys of each series being mountedon the same shaft 31 or 32 respectively, the pulleys being so disposedthat a pulley of the upper set is in the same vertical plane as thepulley on the lower set situated immediately downstream thereof.

At its lower part the drier 14 is provided with an entry opening 33, forhot air of which the temperature is regulated by a thermostat, of whichonly a thermometer 34 is shown in FIG. 1.

The sized and dried slivers or rovings 2" leaves the drier 14 through anoutlet opening 35 provided at its lower end and is wound up on a wind-upbobbin 36, with a friction drive 37 to maintain a constant tension onthe slivers or rovings 2" downstream from the drier 14.

According to one embodiment of the invention, an oiling or waxingapparatus 38 is disposed in the path of the slivers or rovings 2"between the exit 35 of the drier 14 and the rewinding bobbin 36.

One can equally, with advantage, provide an oiling or waxing apparatus38' between the downstream pressure rollers 12, 13 between the entranceto the drier 28.

In certain cases, notably for the acceleration of the roving and whenthe roving is very fragile by virtue of the weak force of cohesionbetween its constituent fibres, it can be advantageous to provide asupport and transport filament constituted preferably from a materialdifferent from that of the slivers or rovings.

In FIG. 1, this support and transport filament 39 unwinds from a bobbin40 and is placed in contact with the slivers or rovings 2 unwinding fromthe bobbin 1 by means of a frusto-conical yarn guide 41, the larger baseof which is directed towards bobbin 1.

The support and transport filament 39 associated with the slivers orrovings 2 passes successively between the upstream pressure rollers 9and 10, through the sizing bath 11a between the downstream pressurerollers 12 and 13 and then into the drier 14.

The support and transport filament 39 and the sized slivers or rovings 2are separated from one another, for example, at the moment where theyreach the first pulley 30 of the lower series of pulleys 30, that is tosay before the sized rovings are completely dried.

At this'moment, the sized slivers or rovings 2' makes a turn around thisfirst pulley 30' and rises towards the following upper pulley 29 whilethe support filament 39 leaves the drier 14 through a lower exit opening42 and is rolled up on a rewind bobbin 43.

According to another embodiment of apparatus, the support and transportfilament can be constituted by an endless filament. As shown in thedrawings in dashed lines in FIG. 1, the endless support and transportfilament 39 leaves the drier 14 through an exit 42 and passessuccessively on a drive roller 44 and on a tensioning roller 45 beforejoining the slivers or rovings 2 in the yarn guide 41 and continues onits path in common with the slivers or rovings 2 until the drier, whereits separation with the said slivers or rovings is effected in the samemanner as in the preceding embodiment.

In FIG. 2, the upstream pressure roller 9 and downstream pressure roller12 as well as the shaft 31 of the upper series 29 of pulleys of thedrier 14 are rotated by a transmission system having a relativeadjustment, by

a drive motor 46 having a fly wheel coupled to its rotor, the said motor46 being, moreover, coupled to a speed variator 47 and provided withreduction gear 48.

This transmission system includes a drive belt 49 connecting the outputshaft 50 on the reduction gear to the shaft 25 of the pressure roller12. This shaft 51 is coupled firstly to the shaft 31 by a V-belt 52,which passes around pulleys 53 and 54 of which one is fixed to the shaft25 and the other to the shaft 31, and, secondly, to the pressure roller9 by a V-belt 55 and passing around pulleys 56 and 57 of which one isfixed to the shaft 24 and the other to the shaft 25 of the pressureroller 12. The discs of the pulleys 53, S4, 57 and 56 are of adjustableseparation and define, between their bevelled peripheral faces grooveshaving a depth adjustable as a function of the spacing between thediscs.

According to FIG. 3, each of the series of the upper pulleys 29 andlower pulleys 30 of the dryer 14 is constituted by a roller of which thefirst disc has a very small coefficient of friction and isanti-adhesive, the roller comprising a series of coaxial annular grooves29', 29" and 30, 30".

The support and transport filament 39 associated with the sized sliversor rovings 2 passes on the first upper pulley 29' and separates from thesized slivers or rovings 2', for example at the moment when the saidsized slivers or rovings 2 reaches the first lower pulley 30.

ln operation, the slivers or rovings 2 are progressively and smoothlyaccelerated by the driven rollers 9 and 12, cooperation with rollers and13, and by the series of driven pulleys 29 of the drier 1. The forceapplied for this purpose on the slivers or rovings 2 is such that itremains always below the natural cohesion force of the fibresconstituting the slivers or rovings 2. The pulling force is preferablybelow 5 to 20 cN. The application of a weak pulling force on the sliversor rovings 2 is possible due to the motor-reduction-gear 46, 48 providedwith a speed changer 47 and by virtue of the very small frictionalforces exercised on the supply bobbin 1. These friction forces are, ingeneral, less than several cN by virtue of the mounting of the bobbin 1between the points 3 located in the ball bearings 4.

The slivers or rovings 2 are thus accelerated progressively until theyreach the predetermined feed speed through the apparatus which can reach30 m/minute or even more.

The mounting of the bobbin 1 on the rotatable frame 5 permits removal ofseveral turns of twist from the slivers or rovings 2. This is, forexample, necessary when the slivers or rovings have been rolled on thebobbin with several turns of twist to give to the fibres of the sliversa better hold, making them suitable for initial winding. It should beunderstood, when one talks of a small twist, one must understand a twistof several turns per meter but this is not comparable with a normaltwist comprising hundreds or even thousands of turns per meter.

The upstream pair of pressure rollers 9 and 10 flattens the slivers orrovings 2 before they are immersed in the bath of size 11a by the diproller 15. Thus, it is possible to force air between the fibres toincrease the surface of contact between the slivers or rovings 2 and thesize.

The downstream pair of pressure rollers 12 and 13 compresses the sizedslivers or rovings 2 after their soaking in the bath of size 11a, thusimproving the distribution of the size into the interior of the saidslivers or rovings and to reject any excess size. It is possible toregulate the degree of flattening of the slivers or rovings by variationof the pressure on the rollers and to regulate the quantity of sizeexpressed from the sized slivers or rovings 2 by an adjustment of thepressure applied by the rollers 12 and 13.

Certain textile fibres undergo, during their dampening by the size, amodification of their length in general, less than 2 percent. To takeinto account any such increase or decrease, the spacing between thediscs of at least one of the pulleys 56, 57 can be regulated in theappropriate sense such that the upstream rollers 9 and 10 turn with aperipheral speed less than or greater than that of the downstreampulleys l2, 13. In a similar fashion, the control of the spacing of thediscs of at least one of the pulleys 53, 54 permits control of the speedof movement of the sized slivers or rovings 2 between downstreampressure rollers 12, 13 and the drier 14. The temperature of the dryingair in the drier 14 is in general between 40C and 150C.

The size bath 11a is of a composition adapted to the nature of thefilaments of the rovings 2 and can contain a plasticising substance, thepurpose of which is to give to the sized and dried slivers or rovings 2the necessary suppleness to permit the use of the said slivers orrovings on a loom or on a knitting machine. The temperature of the sizebath 11a is maintained constant and is, according to the particular sizeused, between 20C and C.

At the outlet to the bath of size 11a and/or of the dryer 14, theslivers or rovings are oiled or waxed, to lubricate the surface of thesized slivers or rovings. According to the particular case, this oilingoperation is effected, either when the sized slivers are still wet and-/or when the sized slivers are already dry.

The support and transport filament 39 or 39 is sometimes necessary tosupport the silvers or rovings 2, at least during the beginning of theunrolling of the slivers or rovings. Nevertheless, one can, in general,interrupt the support and transport filament 39 or 39' after theunwinding of a dozen or so meters of slivers 2, unrolling which issufficient to obtain the speed of passage through the apparatus.

The support filament 39 is separated from the sized slivers 2preferably, when the latter is still wet. This separation is effected,for example, in the heater 14 at the moment the sized slivers or rovings2' and the support filament 39 pass around the second pulley 30 of theheater 14, the pulley 30' being positioned, in the sense of movement ofthe slivers or rovings 2, immediately after the entry 28 into the drier14. At the exit of the drier 14, the dried slivers or rovings 2" arerolled up under regulated tension on the windup bobbin 36 driven by thefriction drive 37.

By way of example, there is indicated here below, the conditions inwhich the slivers or rovings of polyamide, and or polyester, accordingto the invention, can be formed.

1. Material-polyamide fibres of 1.7 dtex Length of fibres40 mm Count ofthe unsized rovings-200 tex Twistseveral turns per meter, thereforepractically no twist Upstream pressure roller force-l daN/cm Temperatureof the size bath-50C Sizing substance5 percent aqueous solution or purepolyvinyl alcohol, of which the degree of polymerisation is between1,700 and 1,800

Normal speed through the apparatusl meters/minute Pressure force of thedownstream rubber pressure roller 9 on the steel roller 10-2.5 daN/cm.per generatrix Drying air heated to 90C Rewinding tensioncN/roving Thispolyamide roving has been worked with success by knitting at a settingof l and 1 on a gauge E8 (needles to the inch) machine at a tightness of12.

cent of a wax known commercially as TRUNAU 914.

The roving of polyester has been worked with success by knitting at asetting of 1 and l on a gauge E8 (needles to the inch) machine at atightness of 10.

3. MaterialWool of which the fibres have a mean diameter of 10 to 20 umCount of the sized rovingsl tex Upstream pressure force-IdaN/cmTemperature of the size bath-50C Sizing substance-aqueous solution of 5percent of pure polyvinyl alcohol of which the degree of 40polymerisation is between 1,700 and 1,800

Sizing substance also comprises a solution of 1/ 100 of anti-formingagent, known under the commercial name NOPCO 1497V Downstream pressureroller force-2.5 daN/cm Spped of passage through the apparatus20m/minute Drying air at a temperature between 80C and 90C.

This roving of wool has been worked with success by return stitchknitting, on gauge E6, tightness 7, 8 or 9.

Textile articles thus obtained can be treated in a bath to eliminate thesize such that the fibres of the rovings recover their initialcharacteristics.

We claim 1. A process for sizing slivers or rovings of textile fibreswhile maintaining said fibres substantially in their initial state asslivers or rovings whereby said fibres may be worked without substantialdeformation, said process comprising the steps of:

a. unwinding the slivers or rovings from a feed bobbin by applying apulling force to the slivers or rovings progressively and smoothly toaccelerate the slivers or rovings to a given speed, said pulling forcealways being less than the cohesion force between the fibresconstituting the slivers or rovings;

b. flattening the silvers or rovings;

c. guiding the slivers or rovings in their flattened state through abath of size;

d. drying the sized slivers or rovings; and

e. winding up the sized and dried slivers or rovings on a rewind bobbin.

2. A process as claimed in claim 1, wherein the pulling force is lessthan 50 cN.

3. A process as claimed in claim 1 and further comprising the step ofturning the slivers or rovings around their axis at several turns permeter during said unwinding thereof, said turning being to the extenteffective for removal of twists existing in said slivers or rovingsprior to said unwinding.

4. A process as claimed in claim 1 and further comprising the step ofoiling the slivers or rovings.

5. A process as claimed in claim 1 and further comprising the step ofsupporting the slivers or'rovings before said flattening step on asupport and transport filament and separating the slivers or rovingsfrom said filament before the end of the drying step.

6. A process as claimed in claim 1, wherein the size is selected fromthe group consisting of a solution of pure polyvinyl alcohol, a solutionof polyvinyl alcohol wherein the polyvinyl alcohol contains acetyl andsulphate groups, and a solution of acrylic copolymer.

7. A process as claimed in claim 6, wherein said size contains aplasticizer.

8. A process as claimed in claim 1, wherein the size is capable of beingdissolved from the sized slivers or rovings when in the dry state.

' UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent 3,79 3Dated February 12 197 4 InVefitOflB) Richard Adrien Schucz et al It iscertified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

.Column 2, line 33, after "being" delete "slivers" and insert in placethereof --less--. Column 2, line 20, "produce" should read --produces-.Column 2, line &0, "lead" should read lend--. Column 3,, line 58,"contro" should read -control-. Column 4, line 26, after "13" insert-and-. Column 5, line 31, "cooperation" should read -cooperating--.Column 5, line 32, "drier 1" should read drier l l-. Column 7, line 1","or" should read -of-. Column 7, line 21, "plymer" should read"polymer"; Column 7, line 42, 1/100" should read- --1/lOO0--.

Signed and sealed this 30th day of July 1974.

(SEAL) Attest: V

MCCOY M. GIBSON; JR. I C. MARSHALL DANN Attes'ting Officer Commissionerof Patents

1. A process for sizing slivers or rovings of textile fibres whilemaintaining said fibres substantially in their initial state as sliversor rovings whereby said fibres may be worked without substantialdeformation, said process comprising the steps of: a. unwinding theslivers or rovings from a feed bobbin by applying a pulling force to theslivers or rovings progressively and smoothly to accelerate the sliversor rovings to a given speed, said pulling force always being less thanthe cohesion force between the fibres constituting the slivers orrovings; b. flattening the silvers or rovings; c. guiding the slivers orrovings in their flattened state through a bath of size; d. drying thesized slivers or rovings; and e. winding up the sized and dried sliversor rovings on a rewind bobbin.
 2. A process as claimed in claim 1,wherein the pulling force is less than 50 cN.
 3. A process as claimed inclaim 1 and further comprising the step of turning the slivers orrovings around their axis at several turns per meter during saidunwinding thereof, said turning being to the extent effective forremoval of twists existing in said slivers or rovings prior to saidunwinding.
 4. A process as claimed in claim 1 and further comprising thestep of oiling the slivers or rovings.
 5. A process as claimed in claim1 and further comprising the step of supporting the slivers or rovingsbefore said flattening step on a support and transport filament andseparating the slivers or rovings from said filament before the end ofthe drying step.
 6. A process as claimed in claim 1, wherein the size isselected from the group consisting of a solution of pure polyvinylalcohol, a solution of polyvinyl alcohol wherein the polyvinyl alcoholcontains acetyl and sulphate groups, and a solution of acryliccopolymer.
 7. A process as claimed in claim 6, wherein said sizecontains a plasticizer.
 8. A process as claimed in claim 1, wherein thesize is capable of being dissolved from the sized slivers or rovingswhen in the dry state.